1. Field of the Invention
The present invention relates to culture media for low-serum or serum-free culture of human or animal cells, and in particular to novel human and/or animal cells culture media which effectively control cell death of cultured human or animal cells when used in the production of biological substances, in biological analysis, or the like.
2. Description of the Prior Art
When industrially useful biological substances such as plasma proteins and antibodies are produced using human and animal cells, or when human and animal cells are used for biological analysis, the serum that is usually added in a concentration of 5 to 10% to the culture medium makes it extremely difficult to purify the product and to make an analysis thereof. Low-serum culture with the addition of minimal amounts of serum or serum-free culture have thus been proposed and developed. Various serum-free culture media have been developed for serum-free culture, most of which involve the addition of alternative substances for the effects of serum, such as transferrin, albumin and similar plasma proteins, steroid hormones, insulin and similar hormones and growth factors, amino acids, vitamins and similar nutrient factors, and the like. Recombinant human and animal cell lines containing a gene for controlling cell death have recently been designed, and there is ongoing research on the serum-free culture of human and animal cell lines which have been genetically engineered to prevent cell death normally induced under serum-free conditions.
Two types of cell death are induced during serum-free culture; cell death induced as a result of starvation due to a lack of nutrient factors, and cell death occurred as a result of apoptosis induced by a lack of specific proteins in serum. However, cell death arising as a result of the induction of apoptosis cannot be addressed with the nutrients conventionally added to serum-free culture, such as transferrin, albumin and similar plasma proteins, steroid hormones, insulin and similar hormones and growth factors, amino acids, vitamins and similar nutrient factors. There is thus a need to develop factors for controlling cell death, including apoptosis.
An object of the present invention is to provide a useful novel human and animal cells culture medium for controlling cell death, including apoptosis, which occurs during serum-free culture when industrially useful biological substances such as plasma proteins and antibodies are produced using human or animal cells or when human or animal cells are used for biological analysis.
As a result of extensive research, the inventors discovered that antithrombin III has considerable effect in controlling cell death, including apoptosis, which occurs during serum-free culture, and this invention has been accomplished according to this discoveries.
That is, the invention is intended to provide novel culture media for the serum-free culture of human or animal cells, containing purified and added antithrombin III from human, bovine, or other animal serum, or antithrombin III from recombinant bacteria or cells containing the full length of the antithrombin III gene.